/Engine/Plugins/Online/OnlineSubsystemUtils/Source/OnlineSubsystemUtils/Public/PartyBeaconHost.h
Handle a reservation update request received from an incoming client
virtual void ProcessReservationUpdateRequest ( [APartyBeaconClient](API\Plugins\OnlineSubsystemUtils\APartyBeaconClient) * Client, const [FString](API\Runtime\Core\Containers\FString) & SessionId, const [FPartyReservation](API\Plugins\OnlineSubsystemUtils\FPartyReservation) & ReservationUpdateRequest, bool bIsRemovingMember )